Communications issues led to challenges during the evacuation of a Regional Express (Rex) Saab 340.
The incident – categorised as serious - occurred on 5 April 2022 as the aircraft (VH-ZRK) prepared to depart from Melbourne, with three crew and 23 passengers aboard, according to the Australia Transport Safety Bureau.
The left engine suffered an interrupted start when the ground power unit was disconnected too early. The interrupted start checklist called for motoring the engine to purge residual fuel.
“During the motoring procedure, the ground crew signalled to the flight crew (using gestures) that they observed flames and smoke coming from the left engine and to shut down the engine,” says the probe.
The captain stopped motoring the engine, which allowed the tailpipe fire that the ground crew had spotted to continue. The captain ordered an evacuation, but crucially did not discuss his observations with the first officer.
“The captain did not use all available information to positively confirm the severity of the situation prior to ordering the evacuation and did not communicate their intent to the first officer.”
Moreover, the single flight attendant was speaking on the public address system when the evacuation decision was made, so the captain used four chimes to announce the evacuation. The chimes, however, were not recognised by the flight attendant, who only learned that an evacuation was required when the pilot opened the cockpit door to communicate directly.
“When the flight attendant then ordered passengers to evacuate, there were limited instructions provided to them,” adds the ATSB.
“As a result, the passengers in the emergency exit row did not open a useable exit which delayed the evacuation of the aircraft. During the evacuation, some passengers took their baggage which increased the risk of injury and delays exiting the aircraft.”
The evacuation took 4min, with all passengers departing through the R1 exit.
Because the issue had not been communicated directly to air traffic control, the arrival of fire services was delayed by 2min.
Ultimately, two passengers suffered minor injuries. An examination of the aircraft revealed no defects or fire damage.
Following the incident, Rex developed a new hand single to indicate an interrupted engine start and provided training for both ground and flight crew.
“The use of all available resources, including seeking input from other crew members, particularly in abnormal or emergency situations, assists in being able to positively identify the nature of a problem,” says the ATSB.
“Undertaking an informed and coordinated approach to decision-making ensures that the most appropriate action can be taken.”
